Author: Doni, Giovanni Battista - manuscripts of italian music theory ...

[--] Which ones are the Mobile and which ones the Stable Notes of the System.
The entire System is composed of stable and mobile notes. As stable notes we
understand the ones which do not move otherwise in the various genera, as Cleonides’
Introduction explains, which occurs by lowering them or raising them proportionately
by tones as it is understood proportionately in the natural notes. Therefore, one has to
know that place is defined in the System as the location, higher or lower, of the voice.
For instance, if we suppose that from the lowest note that one can sing lowering the
voice as much as one can up to the highest he shall be able to produce the span or
interval of two octave, we can imagine for ourselves that there are an infinite number
of places, either higher or lower, according as to whether the voice rises or descends,
in this span contained within the two extremes of these octaves, just as in the example
which I gave above of a string rubbed with a bow (which is alien to music) or divided
into intervals (which one encountered in any melody sung or played) depending on
whether someone pitches a sound higher or lower, we shall say that that note changes
position stopping on a place which is either higher or lower. This same thing is
understood to be happening in the notes of the entire System according to the variety
of the genera, because, since the whole System is divided into four tetrachords and
two extra to comprehend the notes contained within the extremes by the [--]
Tetrachords and by the two Tones. The extreme notes of the Tetrachord and those
which contain the above mentioned tones are called stable or immobile because they
never rise or fall, while all the other ones, namely the two contained in each
Tetrachord, are called Mobile, because, if in a genus they have produce a certain
interval with each other and with the other two immobile ones, when the genus
change they also change place and tension, by descending or ascending. This could be
done in a man-made instrument of four notes by using pegs for the middle notes, as
lute players do nowadays in the notes b fa [sqb] mi when they move from the disjunct
System to the conjunct or the other way round. Therefore, in the disjunct system of
fifteen notes, in which the note b flat is not contained, the stable notes are the two
Hypates, the two nete and the Paranetes with the Netes, which are the extremes of the
tetrachord, and the Proslambanomenos which is outside of the tetrachords, while the
Parhypates and the Lichani as well as the Trites are the mobile ones. And, because, if
the conjunct tetrachord is also included, other notes are added there of which only
one, namely the trite synemmenon, is different in sound, while the other differ only in
name, equally in this tetrachord the Trite [--] and the paranete are mobile, while
the Nete is stable. Therefore, as Bacchius says, the stable notes will be eight, namely
the Proslambanomenos, Hypate Hypaton, Hypate meson, Nete, Paramese, Nete
Synemmenon, Nete Diezeugmenon and Nete Hyperboleon, while, consequently, the
other eight are mobile. And, since two notes of the Synemmenon Tetrachord are in
unison with the other ones of the Diezeugmenon, namely the paranete synemmenon
with the Trite Diezeugmenon and the Mese Synemmenon with the Paranete
Diezeugmenon, this one, as Nete, shall be stable, and, as paranete, shall be monile.
This can be easily gathered from the illustration. Therefore, see with what great
facility, order and with what small number of notes and intervals the wise ancients
constituted the System which embraces all that great variety which contains music.
Therefore, since they wanted to facilitate this perfection instead of confusing it, as
modern theorists have done with a farrago of useless words and signs (especially in
the matter of time signatures) they were satisfied of the same notes and names of the
other two genera by adding the word Diatonic, Chromatic or Enharmonic to the two